1: a preparation containing the virus causing cowpox that is used for vaccination2: a preparation of killed, weakened, or fully infectious microbes that is given (as by injection) to produce or increase immunity to a particular disease

How do you use it?

Vaccines have been developed against diseases caused by bacteria, such as typhoid and tuberculosis, as well as against those caused by viruses, such as measles and rabies.

Are you a word wiz?

"Vaccine" comes from the Latin name for an animal. What animal do you think "vaccine" is named after?

A. chicken

B. monkey

C. zebra

D. cow

We have our bovine friend, the cow, to thank for "vaccine." In the late 1700s, English physician Edward Jenner found that dairy workers who had already had cowpox were immune to smallpox, a much deadlier disease. He began to immunize people from smallpox by injecting them with the material from another person's cowpox sores. In his reports, he called cowpox by its Latin name, "variolae vaccinae." "Vaccinae" comes ultimately from "vacca," the Latin word for "cow." The material used for the injections came to be called "vaccine matter" or "vaccine virus." This was eventually shortened to simply "vaccine."